With development of mobile communications technologies and broadband wireless access technologies, services of the both penetrate into each other. To meet a demand for broadband mobile communications and cope with a challenge of mobile broadband communications, an LTE (Long Term Evolution) communications system is introduced into the mobile communications technologies.
In the LTE communications system, because an OFDM (orthogonal frequency division multiplexing) technology is used, sub-channels are orthogonal with each other, so as to properly solve a problem of intra-cell interference. However, the LTE system has a high requirement on spectrum utilization, and therefore, a manner of single-frequency networking is introduced to improve the spectrum utilization, which, however, introduces a problem of inter-cell interference. For example, if neighboring cells use a same spectrum resource in an overlapping area of their coverage, serious ICI (inter-cell interference) will be caused in the overlapping area. It can be seen that in an LTE communications system, interference affecting system performance is mainly inter-cell interference.
Therefore, how to reduce inter-cell interference for improving service performance of the system, especially performance in a cell edge area, is an important problem to be urgently solved for the LTE system.